Toyota Motor Corp said a partial review of complaints of unintended acceleration after vehicles were repaired for accelerator pedal problems, had found no evidence of failure in the electronic throttle system and or the repairs.

It also said no problems in the brake override system had been found.

U.S. regulators are reviewing more than 60 complaints that fixes made on recalled Toyota cars for unintended acceleration had not solved the problem.

The world largest automaker said in a statement that it had evaluated the cars and interviewed the owners.

Separately, Toyota's technology chief said on Friday that the automaker as not able to get a good grasp of specific details of complaints about its cars.

Toyota also plans to review its research and development process and set up a special team to beef up road tests, said technology chief Takeshi Uchiyamada, joining other key executives in speeches to workers and dealers at the automaker's headquarters in Toyota City.

The Toyota brand is in a deep crisis, he said.

Toyota's North American chief Yoshimi Inaba said the automaker had not been able to dispel concerns about quality during a series of U.S. congressional hearings, while President Akio Toyoda said the company had often just assumed a mantle of success but it would now have to abandon that stance.

Hit by a massive global recall, Toyota executives testified this week and last week before U.S. congressional hearings.

(Reporting by Yoshifumi Takemoto and Nobuhiro Kubo; Editing by Edwina Gibbs)